In the present work, a green, rapid, convenient and eco-friendly method for the synthesis of 2,4,5-trisubstituted imidazoles is described. In this method, we used 1,2-diketone or a-hydroxy ketone, an aldehyde and ammonium acetate in the presence of graphene oxide-chitosan bionanocomposite, which acted as an efficient nanocatalyst. This protocol has many advantages such as short reaction time, high yield, easy separation of the catalyst and solvent-free condition. We used differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and atomic force microscopy (AFM) to confirm that the nanocomposite was formed, and FT-IR, 1 H and 13 C NMR analyses were performed for the confirmation of the synthesized products.Scheme 2 Proposed mechanism for the synthesis of substituted imidazoles 4a-o. Fig. 5 Reusability of GO-chitosan for the synthesis of 2,4,5-triphenyl-1H-imidazole 4a. 33182 | RSC Adv., 2015, 5, 33177-33184 This journal is
The biomedical applications of gold nanoparticles (AuNPs) have experienced rapid growth in recent years, due to their expected benefits in medical imaging and therapy. In this work, we report the development of a theranostic nanocomplex constructed from alginate hydrogel co-loaded with cisplatin and AuNPs (abbreviated as ACA) for simultaneous drug delivery and computed tomography imaging. CT26 cells derived from mouse colon adenocarcinoma were exposed to various concentrations of ACA nanocomplex (for 24 h) and the cytotoxicity was measured using MTT assay. Moreover, the cells treated with ACA nanocomplex were imaged in a computed tomography scanner and the contrast enhancement due to the presence of nanocomplex was assessed. The cytotoxicity results showed that ACA nanocomplex had a more potent chemotherapy efficacy than free cisplatin, so that ACA nanocomplex at the concentration of 5 µg/ml (per cisplatin) and 20 µg/ml of free cisplatin resulted in the same cytotoxicity (survival rate: 66%). The computed tomography imaging study revealed that ACA nanocomplex increased the brightness of computed tomography images, the computed tomography number value, and contrast-to-noise ratio (CNR). ACA nanocomplex can be presented as a computed tomography-traceable nanocarrier that allows to monitor the delivery of therapeutics by assessing their localized accumulation and in vivo biodistribution.
A new cellulose-based nanocomposite was synthesized, characterization and used for the synthesis of imidazoles and α-aminonitriles, and antibacterial property was investigated.
A new "quality-control-based (QC-based) dose survey method" has been developed for determination of diagnostic reference levels (DRL) in Computed Tomography (CT) examinations. The "QC-based dose survey method" is based on the use of retrospective data in the QC documents and reports, which are typically available from the National Regulatory Authority database. The method was applied to 70 CT scanners in Tehran, Iran, by using the available QC reports from the database. The commonly used "data collection method" was also applied by filling each questionnaire on-site to validate the new method. Using the new QC-based and data collection methods, the DRLs of four common CT examinations: head, sinus, chest, and abdomen/pelvis were determined and compared. The DRLs determined by the "QC-based method" for head, sinus, chest, and abdomen/pelvis are 59, 29, 10, and 13 mGy, respectively, for the volume computed tomography dose index (CTDIVol) and 834, 235, 233, and 522 mGy-cm for the dose length product (DLP), respectively. The difference between the DRLs obtained by the two methods is on the average 6.7 ± 5.7%, which is within the acceptance tolerance level of the IAEA for QC dosimetry tests. The "QC-based dose survey method" is believed to be an effective alternative method to the other commonly used "data collection" and "direct dose measurement method" for determination of CT examination DRLs. This new method has unique characteristics such as simplicity, time and cost effectiveness, highly reduced clinical interruptions and collaborations, and potential for large-scale surveys with capability for more frequent review of national DRL values.
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